Process for manufacturing coated filler particles

ABSTRACT

The invention pertains to a process for manufacturing filler modified with functional particles in a high energy blending process through collisions of sufficient energy to bound, adhere, or otherwise associate the pigment particles to the filler.

BACKGROUND OF THE INVENTION

In general, filled polymer materials are desirable for use in a varietyof applications, such as consumer products and polymer compositebuilding materials. Filled polymer materials often employ colorants toimprove the appearance and aesthetic character of the objects into whichthey are formed. Typically, pigments or dyes are added to the polymerbefore it is blended with the filler. However, colored filled polymermaterials are known to fade and undergo aesthetically displeasing colorchanges. One form of aesthetically displeasing color change is known as“whitening”. When objects formed from colored filled polymer materialsare exposed to physical damage, such as scratching, impact, and bending,they are known to change to a white color. The typical mineral fillersthat are used are white in color and it is generally understood that thewhitening is a result of the white filler becoming exposed at thesurface of the object.

In U.S. Pat. No. 7,863,369 Bianchi et al disclose a colored filledpolymer material formed of a polymer matrix and a pigment. The pigmentincludes alumina hydrate particulate having a dye covalently bonded tothe surface of the alumina hydrate particulate. However, materials madeaccording to the disclosure of Bianchi are known to blotch and whiten toan unacceptable degree.

Accordingly, there is a continued need within the industry to providecolored filled polymer materials having improved resistance to whiteningdue to physical damage.

In addition, dispersion of traditional pigments with polymer materialsis difficult. Poor dispersion leads to swirling and color variabilitywith the colored polymer material. Further, poor dispersion of thepigment within the plastic article may lead to undesirable mechanicalproperties. As such, compatibilizers are typically used to dispersepigment within a polymer material. Such compatibilizers include avariety of organic compounds that aid in dispersing the pigment.However, compatibilizers typically are expensive and may also negativelyinfluence mechanical properties of the filled polymer material. Inaddition, pigments are dispersed in liquid prepolymer mixture using highshear mechanical processes which negatively impact the prepolymer andrequire the prepolymer mixture to be deaerated.

In Japanese Patent Application Publication Number 1987030133(A), Kaidediscloses a colored resin composite made from abundant blending ofcolorant with a hydrate of metal oxide beforehand, from which damagedparts do not experience a whitening phenomenon. However, Kaide disclosesa colored hydrate of a metal oxide that is blended with a high molecularweight plastic or rubber material to yield a composite. The presentinvention is a filler modified with particles with an association thatis strong enough to withstand subsequent processing, in particularsuspension and mixing in a polar liquid medium (e.g. methylmethacrylate). A polar liquid media provides a more aggressiveenvironment than the one disclosed in Kaide, and therefore a morechallenging one for modified filler to persist.

Accordingly, there is a continued need within the industry for improveddispersion of colorants and fillers in filled polymer materials whereinthe filler and modifying materials will withstand processing forces.

FIELD OF THE INVENTION

The present invention is related to filler material for polymercomposites.

SUMMARY OF THE INVENTION

One embodiment of the invention is a modified filler particle comprisinga filler particle modified with discrete functional particles that aresufficiently bound, adhered, or otherwise associated to the filler suchthat they are able to remain associated during subsequent manufacturingsteps.

Another embodiment of the invention is a modified filler particlecomprising a filler particle modified with pigment particles that aresufficiently bound, adhered, or otherwise associated to the filler suchthat they are able to remain associated during subsequent manufacturingsteps.

Another embodiment of the invention is a filled polymeric materialcomprising polymer at least partially filled with filler particles thatare modified with functional particles by blending them in a blendingprocess wherein the collisions are of sufficient energy to bound,adhere, or otherwise associate the functional particles to the filler.

BRIEF DESCRIPTION OF FIGURES

FIG. 1 shows SEM micrographs comparing unmodified ATH and ATH modifiedwith various pigments.

FIG. 2 shows SEM micrographs comparing unmodified ATH, iron oxide blackpigment, and ATH modified with iron oxide black pigment viadry-blending.

FIG. 3 shows SEM micrographs comparing unmodified ATH, carbon blackpigment, and ATH modified with carbon black pigment via shaking.

FIG. 4 shows SEM micrographs of Modification of quartz with iron oxideblack via shaking.

FIG. 5 shows an SEM micrograph of Portland cement.

FIG. 6 shows an SEM micrograph of Portland cement modified with ironoxide black via shaking.

FIG. 7 shows an SEM micrograph of alumina.

FIG. 8 shows an SEM micrograph of alumina modified with carbon black.

FIG. 9 shows an SEM micrograph of silicon carbide.

FIG. 10 shows an SEM micrograph of silicon carbide modified with carbonblack.

FIG. 11 shows SEM micrographs of ATH filler dry-blended with pigment andcalcined ATH.

FIG. 12 is a plot of viscosity vs. spindle speed comparing directpigment addition to dry-blended addition of pigment.

FIG. 13 shows the particle size distribution plot of ATH modified withcarbon black made using a horizontal plough mixer.

FIG. 14 shows the particle size distribution plot of ATH (Alcan WH-311).

FIG. 15 shows the particle size distribution plot of a 1:1 (by weight)mixture of carbon black and ATH that was gently combined.

FIG. 16 shows the particle size distribution plot of ATH modified withcarbon black made using a vertical high intensity mixer.

FIG. 17 shows the particle size distribution plot of a carbon blackmodified ATH made using an EIRICH mixer.

FIG. 18 shows an SEM micrograph of ATH simultaneously modified withcarbon black, iron oxide red, and iron oxide yellow via shaking.

FIG. 19 shows an SEM micrograph of ATH modified with Graphtol Fire Redpigment.

FIG. 20 shows an SEM micrograph of ATH modified with titanium dioxide.

FIG. 21 shows an SEM micrograph of ATH modified with 0.2-0.3 micronfumed silica.

FIG. 22 shows an SEM micrograph of ATH modified with 0.007 micron fumedsilica.

FIG. 23 illustrates scratches on various filled polymer materials andhistograms of scans of the scratches.

FIG. 24 is a plot of gray values of scratch scans.

FIG. 25 are photos of Test Plaques before and after hot block testing.

FIG. 26 (prior art) illustrates scratches on various comparative filledpolymer materials and histograms of scans of the scratches.

FIG. 27 (prior art) is a plot of gray values for scratches on variouscomparative filled polymer materials.

DEFINITIONS

As employed herein, the term “solid surface material” is employed in itsnormal meaning and represents a three dimensional material such as amaterial particularly useful in the building trades for kitchencountertops, sinks and wall coverings wherein both functionality and anattractive appearance are necessary. In general, solid surface materialsare composite materials comprised of a polymeric matrix and mineralfiller.

As employed herein, the term “dye” means a colorant that, in general, issoluble in the medium in which it is used, and therefore not of aparticulate nature but rather a multiplicity of solvated molecules.

As employed herein, the term “pigment” means a colorant that isinsoluble in the medium in which it is used, and therefore of aparticulate nature encompassing the physical and chemical propertiesthereof (e.g. surface charge, surface chemistry, and topology).

As employed herein, the term “filler” means any material that is solidat room temperature and atmospheric pressure, used alone or incombination, and which is insoluble in the various ingredients of thecomposition, even when these ingredients are raised to a temperatureabove room temperature and in particular to their softening point ortheir melting point.

As employed herein, the term “calcined ATH” means, alumina trihydrate(ATH) which has been prepared by a thermal treatment process to removewater from its surface.

As employed herein, the term “discrete functional particle” means amaterial that is 1) not soluble in the medium in which it is used andtherefore in that medium does not exist as a multiplicity of individualsolvated molecules and 2) one that can modify another solid material.

As described herein, the term “modified” means having associated one ormore discrete functional particles.

As employed herein, the term “associated” means held in close proximityto a surface via an interaction including both non-bonding interactions,such as van der waals forces, ion-dipole interactions, dipole-dipoleinteractions, capillarity, and electrostatic interactions, and alsobonding interactions, such as covalent bonding, ionic bonding, hydrogenbonding, metallic bonding, acid-base interactions, Pearson-typeacid-base interactions, and dative (coordinate covalent) bonding.

DETAILED DESCRIPTION OF THE INVENTION

A first embodiment of the invention provides a filler particle modifiedwith discrete functional particles for incorporation into filled polymermaterials. The filler particle is modified with discrete functionalparticles by dry-blending discrete functional particles and filler in ahigh energy mixing process prior to incorporating the resulting modifiedfiller into a liquid prepolymer mix. It is found that the dry-blendingof discrete functional particles with filler prior to incorporation intoa liquid prepolymerized mixture provides for a modified filler particlewith improved processing and performance characteristics. The energyimparted by the blending process must be of sufficient energy to bound,adhere, or otherwise associate the functional particles to the filler.

Another embodiment of the invention provides a filler particle modifiedwith pigment particles for incorporation into filled polymer materials.The filler particle is modified with pigment by dry-blending discretepigment particles and the filler by employing a high energy mixingprocess prior to incorporating the resulting modified filler into aliquid prepolymer mix. The energy imparted by the dry-blending processmust be of sufficient energy to bound, adhere, or otherwise associatethe pigment particles to the filler. It is found that the dry-blendingof pigment particles with filler prior to incorporation into a liquidprepolymerized mixture provides for a pigmented filler particle withimproved processing and performance characteristics when compared todyeing the filler, or by incorporating a liquid pigment dispersion to aprepolymerized mix. It is also found that objects made with filledpolymer materials employing the dry-blended pigment-modified filler haveimproved resistance to whitening due to physical damage. It is alsofound that the dry-blending of pigment with filler prior toincorporation into a liquid prepolymerized mixture provides improveddispersion of colorants in colored filled polymer materials wherein themodified filler will withstand processing forces better than dyed filleror liquid pigment dispersions. It is also found that dry-blendingmodified filler particles provides a means for introducing a highloading of pigment, to a level that direct addition of pigment does notpermit. High pigment loading via dry-blended filler is found to beeconomical and convenient, whereas it is found that adding a high levelof pigment via a traditional dispersion is costly and impractical giventhe relatively low concentration of pigment that can be dispersed bythose skilled in the art.

Another embodiment of the invention provides filled polymeric materialscomprising polymer at least partially filled with filler particles thatare modified with functional particles by blending them in adry-blending process wherein the collisions are of sufficient energy tobound, adhere, or otherwise associate the functional particles to thefiller. The dry-blending process is done prior to incorporating theresulting modified filler into a liquid prepolymer mix. Variousfunctional properties are incorporated into the filled polymer materialdependent on the material used to modify the filler. It is found thatdry-blending discrete particles and a filler in a high energy mixingprocess prior to incorporation into liquid prepolymer mixture provides afiller particle that more strongly bonds with the discrete functionalparticles than will be the case for dyed filler or filler that is mixedwith discrete functional particles in a low energy mixing process.

The modified filler particle includes particulate filler. In general,this filler increases the hardness, stiffness or strength of the finalarticle relative to the pure polymer or combination of pure polymers.The filler is insoluble in the various ingredients of typical liquidprepolymers. Some representative fillers include alumina, aluminatrihydrate (ATH), alumina monohydrate, aluminum hydroxide, aluminumoxide, aluminum sulfate, aluminum phosphate, aluminum silicate, Bayerhydrate, borosilicates, calcium sulfate, calcium silicate, calciumphosphate, calcium carbonate, calcium hydroxide, calcium oxide, apatite,quartz, quartzite, silica (SiO₂, including sand), glass bubbles, glassmicrospheres, glass fibers, glass beads, glass flakes, glass powder,glass spheres, carbon fibers, ceramic fibers, metal fibers, polymerfibers, nano-wood fibers, carbon nanotubes, graphene, clay, bariumcarbonate, barium hydroxide, barium oxide, barium sulfate, bariumphosphate, barium silicate, magnesium sulfate, magnesium silicate,magnesium phosphate, magnesium hydroxide, magnesium oxide, kaolin,montmorillonite, bentonite, pyrophyllite, mica, gypsum, ceramicmicrospheres and ceramic particles, powder talc, titanium dioxide,diatomaceous earth, wood flour, borax, silicon carbide, Portland cement,or combinations thereof. The filler is present in the form of smallparticles, with an average particle size in the range of from about0.1-500 microns. The preferred filler is a mineral particle. Aparticularly preferred filler is alumina trihydrate. Anotherparticularly preferred filler is quartz.

The modified filler particle includes discrete functional particles. Thefunctional particles may be any natural or synthetic, organic orinorganic matter, usually in the form of an insoluble powder. Functionalparticles may be any combination of functional particles.

A preferred discrete functional particle is pigment. When the filler ismodified with pigment and the subsequent modified filler particle isincorporated into a polymeric material, it is found to impart improvedcolorant characteristics. When modifying the filler with pigment, thepreferred pigments are iron oxides and carbon black.

Other useful discrete functional particles are energy absorptionmodifiers. Energy absorption modifiers include UV absorption modifiers,UV stabilization modifiers, IR absorption modifiers, radiofrequency waveabsorption modifiers, fluorescent response modifiers, phosphorescentresponse modifiers, thermochromism modifiers, electrical conductivitymodifiers, magnetic characteristic modifiers, or any combinationthereof.

Other useful discrete functional particles are mechanical propertymodifiers. Mechanical property modifiers include surface hardnessmodifiers, lubricity modifiers, strength modifiers, toughness modifiers,impact resistance modifiers, scratch resistance modifiers, marresistance modifiers, and any combination thereof.

Other useful discrete functional particles are materials that modify thesurface properties of the filler particles. Surface property modifiersinclude stain resistance modifiers, lubricity modifiers, adhesionmodifiers, absorbability modifiers, flame retardants, antimicrobialagents, modifiers of self-cleanability, modifiers of self-healing of apolymeric matrix comprising the modified filler particle, acidity oralkalinity modifiers, modifiers of electrical characteristics, modifiersof magnetic properties, or any combination thereof.

Other useful discrete functional particles are materials that modify theinteraction of the filler particles with a surrounding medium when themodified filler particle is added to the medium. Useful materialsinclude surface tension modifiers, rheology modifiers, modifiers of theagglomeration state of the modified filler particle, modifiers of thepacking efficiency of the modified filler particle, compatibilizers,dispersants, or any combination thereof.

In the present invention, particles are present in two different sizedistributions. It is considered that the benefits of modifying thefiller particle with functional particles do not occur to the desireddegree if the particle size distribution is not present. A particle sizedistribution for the filler is in a range from 0.1 micron to 100microns, more preferably 7 to 100, and most preferably 10 to 50 microns.

A particle size distribution for the functional particles is from 0.005microns to 4 microns, more preferably from 0.01 to 3 microns. It isbelieved that most commercial pigments are in the 0.2 to 3 micron range.

The ratio of the filler to the functional particles may range on aweight basis from 99.9:0.1 up to 10:90.

The dry-blending process employs a high energy mixing process. A highenergy mixing process mixes the functional particles and filler to ahomogeneous mixture in 60 minutes or less. Without being bound totheory, it is believed that a high energy mixing process creates a bondbetween pigment and filler that is stronger than low energy mixingprocesses. A suitable high shear mixing process is an air drivenpitch-blade turbine with a high shaft speed. A suitable shaking processemploys a paint shaker run at a high speed. Optional mixing processesinclude microwave blending, shaking, tumbling, milling (jet, ball),supercritical fluids, homogenizer, electrostatic fields, magneticfields: horizontal plough mixer, vertical high intensity mixer,horizontal or vertical blade mixer, EIRICH-type mixer, pin mill, hammermill, fluidized bed, vibratory, sonication, blenders (V-shaped, doublecone), or a combination thereof.

The preferred use of the dry-blended modified filler of the presentinvention is in a solid surface material. Solid surface materials arefilled polymeric materials and various methods for their manufacture areknown in the art. The preferred solid surface material is an acryliccontaining composition. The preparation of a polymerizable acryliccomposition consisting essentially of a syrup containing methylmethacrylate polymer dissolved in monomeric methyl methacrylate(polymer-in-monomer syrup), a polymerization initiator, and inorganicfiller, preferably alumina trihydrate, is disclosed in U.S. Pat. No.3,847,865 issued to Ray B. Duggins. The composition can be cast ormolded and cured to produce a sheet structure with an importantcombination of properties including translucency, weather resistance,resistance to staining by common household materials, flame resistance,and resistance to stress cracking. In addition, the cured article can beeasily machined by conventional techniques including sawing and sanding.This particular combination of properties makes such a structureparticularly useful as kitchen or bathroom countertops, back splashpanels, molded articles such as towel racks, and the like. The polymerconstituent comprises 15 to 80%, preferably 20 to 45% by weight of thefilled article and may comprise methyl methacrylate homopolymers andcopolymers of methyl methacrylate with other ethylenically unsaturatedcompounds (e.g., vinyl acetate, styrene, alkyl acrylates, acrylonitrile,alkyl methacrylates, multifunctional acrylic monomers such as alkylenedimethacrylates and alkylene diacrylates). In addition, the polymerconstituent can contain small amounts of other polymers including minoramounts of polyester. The solid surface material also contains 20 to85%, preferably about 55 to 80% of filler. The preferred filler is thedry-blended filler of the present invention. Optional materialsgenerally used as fillers may be combined in the liquid prepolymermixture along with the dry-blended filler, for example, titanates,barium sulfates, calcium carbonate, lithopone, china clays, magnesite,mica, iron oxides, silicone dioxide, and various siennas. Optionally,the solid surface material may contain macroscopic decorative particlesknown to the industry as “crunchies”. Crunchies are various filled andunfilled, pigmented or dyed, insoluble or crosslinked chips of polymerssuch as ABS resins, cellulose esters, cellulose ethers, epoxy resins,polyethylene, ethylene copolymers, melamine resins, phenolic resins,polyacetals, polyacrylics, polydienes, polyesters, polyisobutylenes,polypropylenes, polystyrenes, urea/formaldehyde resins, polyureas,polyurethanes, polyvinyl chloride, polyvinylidene chloride, polyvinylesters and the like. Other useful macroscopic translucent andtransparent decorative particles are natural or synthetic minerals ormaterials such as agate, alabaster, albite, calcite, chalcedony, chert,feldspar, flint quartz, glass, malachite, marble, mica, obsidian, opal,quartz, quartzite, rock gypsum, sand, silica, travertine, wollastoniteand the like; cloth, natural and synthetic fibers; and pieces of metal.When incorporating the dry-blended modified filler into liquidprepolymer mixtures, various filler materials modified with variouspigment materials may be combined. Optional uses of the dry-blendedfiller include cable coating, carpet backing, and concrete.

The dry-blended modified filler may be combined with polymeric matricesusing processes other than liquid prepolymer, such as casting, meltprocessing, powder coating, solution processing, slip casting, tapecasting, vibrocompaction, compression molding, sintering, extrusion, andinjection molding.

The following examples are included as representative of the embodimentsof the present invention.

EXAMPLES Example 1 Modification of ATH with Pigment Particles ViaShearing

In eight separate preparations, a 1-quart vessel was charged with 217.5g of alumina trihydrate (Alcan WH-311). While stirring at 500 RPM with afour-blade air driven pitch-blade turbine, 32.5 g of a given solidpigment was added over the course of 15 minutes. Mixing was continueduntil the mixture appeared to be homogenously colored. SEM micrographswere acquired for each sample of modified filler:

Figure of SEM Pigment Micrograph NONE; unmodified ATH lA BASF MagneticBlack S 0045 1B Iron Oxide Yellow 1888D 1C Kroma Red 3097 1D IrgazinBlue 3367 lE Monolite Green 751 1F Meteor Bright Yellow 8320 1GQuinacridone Red Violet 19 1H Arosperse F138 Carbon Black 1I

The micrographs demonstrate that a shearing process is effective inmodifying a filler with a pigment, and that the dry-blending processworks on organic, inorganic and carbon black pigments.

Each of the eight samples of the dry-blended pigment-modified fillerswas then subjected to washing in methyl methacrylate to ensurepersistence of the pigment modification in a manufacturing process.Specifically, the test is designed to determine if the pigment woulddisassociate from the filler and cause color blotches in objects madefrom liquid prepolymers incorporating the modified filler. In each case,10.0 g of the modified filler was placed in a 40-mL glass vial. To thiswas added 30.0 g of methyl methacrylate. The vials were capped andplaced on a wrist-action shaker table for four hours. Thefully-suspended mixtures were cast into shallow aluminum pans. The bulkmethyl methacrylate was allowed to evaporate. Following this, thesamples were placed in a drying oven at 45° C. for one hour. Thetemperature of the oven was increased ˜10° C. every hour for four hours.The total drying time was 6 hours. Visual inspection confirmed that forall eight samples the pigment remained on the filler. The micrographsshow that the pigment persisted with an association that is strongenough to withstand subsequent processing, in particular suspension andmixing in a polar liquid medium. SEM micrographs were acquired for threeof the dried samples:

Figure Reference Washed, Cast, Initial and Dried Sample Sample SampleATH Modified with Iron Oxide Yellow 1888D 2A 2B ATH Modified withArosperse F138 Carbon Black 2C 2D ATH Modified with Quinacridone RedViolet 19 2E 2F

Example 2 Modification of ATH with Iron Oxide Black Via Shaking

A one-gallon paint can was charged with 1,500 g ATH and 714.3 gBayferrox 318 NM (iron oxide black). The vessel was sealed and thenshaken on a Red Devil single-arm paint shaker for 30 minutes at whichpoint the components appeared to be homogeneously blended. The samplewas analyzed by SEM (FIG. 3C). The micrograph shows the presence ofrelatively small iron oxide black particles on the surface of therelatively large ATH particles. This demonstrates that a shaking processis effective in modifying a filler with a functional particle.

Example 3 Modification of Quartz with Iron Oxide Black Via Shaking

A one-gallon paint can was charged with 217.5 g of Blackburn 84 meshquartz and 32.5 g of Bayferrox 318 NM (iron oxide black). The vessel wassealed and then shaken on a Red Devil single-arm paint shaker for 30minutes at which point the components appeared to be homogeneouslyblended. The sample was analyzed by SEM (FIG. 4B) along with anunmodified sample of quartz (FIG. 4A) The micrographs show the presenceof relatively small iron oxide black particles evenly distributed on thesurface of the large quartz particles, indicating a homogeneous blend.

The modified sample was subjected to the methyl methacrylate washingprocedure of Example 1. An SEM micrograph of the washed, cast, and driedsample was acquired (FIG. 4C). The micrograph shows that the pigmentmodification persisted with an association that is strong enough towithstand subsequent processing, in particular suspension and mixing ina polar liquid medium.

Example 4 Modification of Portland Cement with Iron Oxide Black ViaShaking

A one-gallon paint can was charged with 1,224 g Portland cement(Quikrete) and 576 g iron oxide black (Bayferrox 318). The vessel wassealed and then shaken on a Red Devil single-arm paint shaker for 60minutes. The sample was a fine free-flowing uniformly dark black powder.Analysis by SEM revealed the presence of small iron oxide particles onthe surface of the cement (see FIG. 5 (unmodified cement) versus FIG. 6(cement modified with iron oxide black)).

This demonstrates that a mixture of inorganic compounds, such asPortland cement, can be modified by functional particles using theprocesses described here.

Example 5 Modification of Alumina with Carbon Black via Shaking

A one-gallon paint can was charged with 1,757.5 g alumina (C-1, 87micron, Rio Tinto Alcan) and 42.5 g Arosperse F138 carbon black. Thevessel was sealed and then shaken on a Red Devil single-arm paint shakerfor 60 minutes. The sample was a fine free-flowing uniformly dark blackpowder. Analysis by SEM revealed the presence of small carbon blackparticles on the surface of the alumina (see FIG. 7 (unmodified alumina)versus FIG. 8 (alumina modified with carbon black)).

This further demonstrates that a metal oxide filler can be modified byfunctional particles using the processes described here.

Example 6 Modification of Silicon Carbide with Carbon Black Via Shaking

A one-gallon paint can was charged with 1,757.5 g silicon carbide (BlackSilicon Carbide Grain, 80 micron, Silicon Carbide Products) and 42.5 gArosperse F138 carbon black. The vessel was sealed and then shaken on aRed Devil single-arm paint shaker for 60 minutes. The sample was a finefree-flowing uniformly dark black powder. Analysis by SEM revealed thepresence of small particles on the surface of the silicon carbide (seeFIG. 9 (unmodified silicon carbide) versus FIG. 10 (silicon carbidemodified with carbon black)).

This demonstrates that a carbide compound can be modified by functionalparticles using the processes described here.

Example 7 Modification of ATH with Carbon Black Via Shaking, andSubsequent Processing

A one-gallon paint can was charged with 1,500 g ATH and 36.3 g ArosperseF138 (carbon black). The vessel was sealed and then shaken on a RedDevil single-arm paint shaker for 30 minutes to create a dry-blendedmodified filler. A sample of the modified filler was analyzed by SEM(FIG. 11C). The micrograph shows the presence of relatively small carbonblack particles evenly distributed on the surface of the relativelylarge ATH particles.

A first test sample was prepared by combining a first 125 g sample ofthe above mixture with 125 g of unmodified ATH in a one quart vessel anddry-blending them in a Red Devil single-arm paint shaker for 30 minutesto create dry-blended modified filler. A second sample was prepared bycombing a second 125 g sample of the above mixture combined with 125 gof calcined ATH in a one quart vessel and dry-blending them in a RedDevil single-arm paint shaker for 30 minutes to create dry-blendedmodified filler. The calcined ATH had been prepared by heating ATH to800° C. for 24 hours to remove all three water molecules of hydration.Both samples were analyzed by SEM. The micrograph of the first samplecomprised of carbon black-modified ATH dry-blended with an equal weightof unmodified ATH (FIG. 11D) shows an even coating of carbon blackparticles on all ATH particles, similar to what is shown in FIG. 11C.However, the micrograph of the second sample comprised of carbonblack-modified ATH dry-blended with an equal weight of calcined ATH(FIG. 11E) shows a mixture of particles with different surfacemorphologies, some exhibiting rigidly geometric and sharp edges (FIG.11F), others exhibiting relatively smooth edges (FIG. 11G). The formerare unmodified particles of calcined ATH, the latter being intactmodified particles of ATH. This shows that carbon black particlespresent on the surface of dry-blended ATH can redistribute amongunmodified ATH particles when subjected to dry-blending. However, whencarbon black-tinted ATH particles are combined with calcined ATH anddry-blended, the carbon black particles remain on the surface of thedry-blended pigment-modified ATH and do not redistribute among thecalcined ATH. Thus, the forces involved in typical polymer processingare of insufficient energy to redistribute pigment among fillers withvastly different surface chemistries. The pigment will remain with thefiller to which it is modified during dry-blending. This demonstratesthat the dry-blended pigment-modified filler will withstand processingforces.

Example 8 Modification of ATH with Quinacridone Red Violet Via Shakingand Formation of a Filled Acrylic Composite Using the Modified Filler

A one-gallon paint can was charged with 1,500 g of ATH (Alcan WH-311)and 24.20 g of quinacridone red violet 19 (Lansco Colors). The vesselwas sealed and then shaken on a Red Devil single-arm paint shaker for 30minutes to create a first batch. This procedure was repeated a secondtime to create a second batch. The first batch and the second batch werecombined to form a test batch of dry-blended filler.

An experimental Test Plaque (Test Plaque 8A) was prepared from a liquidprepolymer mixture consisting of 87.0 g methyl methacrylate (MMA), 260.9g of a 24 wt. % acrylic polymer solution (polymethyl methacrylate ofmolecular weight approximately 30 kg/mol dissolved in MMA), 4.3 gtrimethylolpropane trimethacrylate, 10.0 g tert-butylperoxymaleic acid(PMA-25, Arkema), 0.7 g of Zelec PH unsaturated phosphoric acid ester(Stepan Co.) and 1.5 g AOT-S(Cytec) was blended at room temperature.While stirring at 300 rpm with an air-driven pitch blade turbine, 630.0g of the dry-blended quinacridone red modified ATH filler describedabove was added over one minute. Mixing was continued for two additionalminutes. The resultant mixture was transferred to an enclosed vesselwhere dissolved gases were removed in vacuo (24 inHg) over a period oftwo minutes while stirring at 1,000 rpm. While still under vacuum, 4.2 gof a calcium hydroxide suspension (45 wt. % in solvent) was added viasyringe through a rubber septum. This was immediately followed byaddition of 1.6 g ethylene glycol dimercaptoacetate (GDMA). After mixingfor 30 seconds, the vacuum was released and the mixture was poured intoa film-lined casting cavity which was pre-heated to 35° C. Film wasplaced on the backside of the casting, and an insulated cover was placedon top. The mixture cured within 15 minutes. After allowing theresultant plaque to cool to room temperature, it was rough-finished in adrum sander and then sanded with progressively finer grit sand paperending with 4000-grit to create Test Plaque 8A.

A control Test Plaque (Test Plaque 8B) of a liquid dispersion pigmentedfilled polymeric material was prepared from a liquid prepolymer mixtureprepared in the same manner as above. While stirring at 300 rpm with anair-driven pitch blade turbine, 620.0 g of unmodified ATH (Alcan WH-311)was added over one minute. Mixing was continued for two additionalminutes. Afterwards, 10.0 g of quinacridone red violet 19 (Lansco Color)was added to the stirring mixture over one minute. Mixing was againcontinued for two additional minutes. The resultant mixture wastransferred to an enclosed vessel where dissolved gases were removed invacuo (24 inHg) over a period of two minutes while stirring at 1,000rpm. While still under vacuum, 4.2 g of a calcium hydroxide suspension(45 wt. % in solvent) was added via syringe through a rubber septum.This was immediately followed by addition of 1.6 g ethylene glycoldimercaptoacetate (GDMA). After mixing for 30 seconds, the vacuum wasreleased and the mixture was poured into a film-lined casting cavitywhich was pre-heated to 35° C. Film was placed on the backside of thecasting, and an insulated cover was placed on top. The mixture curedwithin 15 minutes. After allowing the resultant plaque to cool to roomtemperature, it was rough-finished in a drum sander and then sanded withprogressively finer grit sand paper ending with 4000-grit to create TestPlaque 8B.

A Hunter Miniscan spectrophotometer was used to measure the color ofboth Test Plaques. The L, a, b color space is used to describe the colormeasurement where the 1′ value is a measure of lightness (low ‘L’ isdark, high 1′ is light), the ‘a’ value represents the red/green axis(negative ‘a’ is toward a green hue, positive ‘a’ is toward a red hue)and the ‘b’ value represents the yellow/blue axis (negative ‘b’ istoward a blue hue, positive ‘b’ is toward a yellow hue). The differencein color between two samples (or a single sample before and after aphysical test) can be represented as the change in each color axis: ΔL,Δa, and Δb. Alternatively, the root-mean-square average of the threedelta-values can be calculated to give a total color difference, ΔE. Asshown in Table 1, there is a significant difference in the color of thecomposites, despite an equal loading of pigment. In particular, the Lvalue for the composite of Test Plaque 8B is two units higher (lighter)than that of Test Plaque 8A. This represents a difference in tintingstrength of the pigment, indicating a poor dispersion of pigmentparticles in 5B.

TABLE 1 L a b color values L a b Test Plaque 8A (dry-blended) 31.1528.02 8.23 Test Plaque 8B (liquid dispersion) 33.22 31.25 8.92

Example 9 Modification of ATH with Carbon Black Via Shaking andFormation of a Filled Acrylic Composite Using the Modified Filler

A one-gallon paint can was charged with 1,500 g ATH (Alcan WH-311) and36.3 g Arosperse F138 carbon black (Evonik). The vessel was sealed andthen shaken on a Red Devil single-arm paint shaker for 30 minutes tocreate a first batch of modified filler. This procedure was repeated asecond time, the resulting batch of modified filler being combined withthe first batch to create a total batch of dry-blended filler.

An experimental Test Plaque (Test Plaque 9A) was prepared from a liquidprepolymer mixture consisting of 85.8 g methyl methacrylate (MMA), 257.3g of a 24 wt. % acrylic polymer solution (polymethyl methacrylate ofmolecular weight approximately 30 kg/mol dissolved in MMA), 4.2 gtrimethylolpropane trimethacrylate, 9.9 g tert-butylperoxymaleic acid(PMA-25, Arkema), 0.7 g of Zelec PH unsaturated phosphoric acid ester(Stepan Co.) and 1.5 g AOT-S(Cytec) was blended at room temperature.While stirring at 300 rpm with an air-driven pitch blade turbine, 635.0g of the carbon black modified ATH described above was added over oneminute. Mixing was continued for two additional minutes. Brookfieldviscosity of the mixture was measured at this point (RV-DV-II, S-72 vanespindle, 21-22° C.) and is shown in FIG. 12. The mixture was thentransferred to an enclosed vessel where dissolved gases were removed invacuo (24 inHg) over a period of two minutes while stirring at 1,000rpm. While still under vacuum, 4.1 g of a calcium hydroxide suspension(45 wt. % in solvent) was added via syringe through a rubber septum.This was immediately followed by addition of 1.6 g ethylene glycoldimercaptoacetate (GDMA). After mixing for 30 seconds, the vacuum wasreleased and the mixture was poured into a film-lined casting cavitywhich was pre-heated to 35° C. Film was placed on the backside of thecasting, and an insulated cover was placed on top. The mixture curedwithin 15 minutes. After allowing the resultant plaque to cool to roomtemperature, it was rough-finished in a drum sander and then sanded withprogressively finer grit sand paper ending with 240-grit to create TestPlaque 9A, a filled polymeric material pigmented with dry-blendedfiller.

A control Test Plaque (Test Plaque 9B) was prepared from a liquidprepolymer mixture prepared in the same manner as above. While stirringat 300 rpm with an air-driven pitch blade turbine, 620.0 g of unmodifiedATH (Alcan WH-311) was added over one minute. Mixing was continued fortwo additional minutes. Afterwards, 15.0 g of Arosperse F138 was addedto the stirring mixture over one minute. Mixing was again continued fortwo additional minutes. Brookfield viscosity of the mixture was measuredat this point (RV-DV-II, S-72 vane spindle, 21-22° C.) and is shown inFIG. 12. The mixture was then transferred to an enclosed vessel wheredissolved gases were removed in vacuo (24 inHg) over a period of twominutes while stirring at 1,000 rpm. While still under vacuum, 4.1 g ofa calcium hydroxide suspension (45 wt. % in solvent) was added viasyringe through a rubber septum. This was immediately followed byaddition of 1.6 g ethylene glycol dimercaptoacetate (GDMA). After mixingfor 30 seconds, the vacuum was released and the mixture was poured intoa film-lined casting cavity which was pre-heated to 35° C. Film wasplaced on the backside of the casting, and an insulated cover was placedon top. The mixture cured within 15 minutes. After allowing theresultant plaque to cool to room temperature, it was rough-finished in adrum sander and then sanded with progressively finer grit sand paperending with 240-grit to create Test Plaque 9B, a filled polymericmaterial with pigment added directly to the liquid prepolymer mixture.

A plot of the viscosity of the liquid prepolymer mixture vs. the spindlespeed of the air-driven pitch blade turbine is given in FIG. 12 for bothof the Test Plaques. The mixture of Test Plaque 9B (where carbon blackwas added directly to the batch) exhibits a higher viscosity at allspindle speeds and, further, exhibits significant shear thinningbehavior than that of Test Plaque 9A.

Test Plaque 9A was of high visual quality, exhibiting a uniform blackappearance. Test Plaque 9B was of poor visual quality, exhibiting darkspots visible on all surfaces of the plaque. The dark spots weredetermined to be agglomerated pigment under visual inspection.

A Hunter Miniscan spectrophotometer was used to measure the color ofboth Test Plaques. As shown in Table 2, there is a significantdifference in L color of the composites, despite an equal loading ofpigment. The L value of Test Plaque 9B is 1.13 units lighter than thatof Test Plaque 9A, again indicating that adding the pigment directly tothe ATH-containing mixture results in poor dispersion of the pigmentand, thus, low tinting strength.

TABLE 2 L a b Color Values L a b Composite of Test Plaque 9A 24.90 −0.25−1.63 Composite of Test Plaque 9B 26.03 −0.37 −2.00

This demonstrates that dry-blending provides a means for introducing afunctional particle (such as a pigment) into a liquid prepolymer mixturein a manner that achieves enhanced color characteristics when comparedto traditional direct addition to the liquid prepolymer mixture.

It also demonstrates that the addition of pigment directly into theliquid prepolymer results in agglomerate formation and a reduction inthe tinting strength of the pigment as compared to the addition ofpigment to a filled prepolymer mixture by first bonding the pigment tofiller by dry-blending them before combining with the liquid prepolymer.

It also demonstrates that the addition of pigment to a filled prepolymermixture by first bonding the pigment to filler by dry-blending thembefore combining with the liquid prepolymer results in a significantdecrease in the viscosity of the mixture. Decreased viscosity of theprepolymer is beneficial to manufacturing processes that are required inorder to form objects from the prepolymer.

Example 10 Modification of ATH with Carbon Black Using a CommercialScale Horizontal Plough Mixer with Chopper and Formation of a FilledAcrylic Composite Using the Modified Filler

A 130-L Littleford Day horizontal plough mixer (model FM-130), equippedwith an 4-blade inverted Christmas tree chopper (4 inch, 6 inch, 7 inch,7 inch) was charged with 172.5 lbs of ATH (Alcan WH-311) and 4.13 lbs ofArosperse F-138 carbon black (Evonik). The mixer was run with a ploughspeed of 155 rpm and a chopper speed of 3,400 rpm. A sample of themixture was taken after 5 minutes. The sample was a fine free-flowinguniformly dark powder. Analysis by SEM revealed the presence of carbonblack on the surface of the ATH, comparable to what is depicted formaterials generated using small scale methods, such as shaking.

The sample was subjected to particle size analysis via light scatteringusing a Malvern Mastersizer 2000. The sample was measured in water withsodium metaphosphate as dispersant. The particle size distribution (PSD)is shown in FIG. 13. It nearly overlays the PSD of the unmodified ATHwhich is depicted in FIG. 14. In contrast, a sample made by combiningATH and carbon black (1:1 by weight) and then gently and manually mixingyields a sample with a bimodal and broad PSD (FIG. 15). As expected, afunctional particle-modified filler made by the processes described heregives a single unimodal PSD curve while a simple mixture of the same twocomponents gives a broad, bimodal PSD curve.

The sample was used to cast an experimental Test Plaque (Test Plaque10-A). This was prepared from a liquid prepolymer mixture consisting of83.4 g methyl methacrylate (MMA), 264.00 g of a 24 wt. % acrylic polymersolution (polymethyl methacrylate of molecular weight approximately 30kg/mol dissolved in MMA), 4.26 g trimethylolpropane trimethacrylate,7.10 g tert-butylperoxymaleic acid (PMA-25, Arkema), 0.68 g of Zelec PHunsaturated phosphoric acid ester (Stepan Co.) and 1.50 g AOT-S(Cytec)which were blended at room temperature. While stirring at 300 rpm withan air-driven pitch blade turbine, 635.0 g of the carbon black modifiedATH described above was added over one minute. Mixing was continued fortwo additional minutes. The mixture was then transferred to an enclosedvessel where dissolved gases were removed in vacuo (24 inHg) over aperiod of two minutes while stirring at 1,000 rpm. While still undervacuum, 2.98 g of a calcium hydroxide suspension (45 wt. % in solvent)was added via syringe through a rubber septum. This was immediatelyfollowed by addition of 1.11 g ethylene glycol dimercaptoacetate (GDMA).After mixing for 30 seconds, the vacuum was released and the mixture waspoured into a film-lined casting cavity which was pre-heated to 35° C.Film was placed on the backside of the casting, and an insulated coverwas placed on top. The mixture cured within 15 minutes. After allowingthe resultant plaque to cool to room temperature, it was rough-finishedin a drum sander and then sanded with progressively finer grit sandpaper ending with 500-grit to create Test Plaque 10-A, a filledpolymeric material pigmented with dry-blended filler. The Test Plaquewas of high quality, exhibiting uniform coloration and no visualdefects.

This demonstrates that a horizontal plough mixer is an effective machineto modify a filler with a functional particle.

Example 11 Modification of ATH with Carbon Black Using a CommercialScale Vertical High Intensity Mixer

A 180-L Littleford Day vertical high intensity mixer (Model W-180) wascharged with 200 lbs of ATH (Alcan WH-311) and 4.92 lbs of ArosperseF-138 carbon black (Evonik). The mixer was run with a plough speed of900 rpm. A sample of the mixture was taken after 5 minutes. The samplewas a fine free-flowing uniformly dark powder.

The sample was subjected to particle size analysis using the sametechnique as described in Example 10. The PSD is depicted in FIG. 16.The curve is relatively narrow and unimodal indicating that a singleparticulate material was generated through modification of the filler(ATH) with a functional particle (carbon black).

The sample was used to cast an experimental Test Plaque (Test Plaque11-A). The same formulation, casting procedure, and plaque finishingprocedure described in Example 10 were used. The Test Plaque was of highquality, exhibiting uniform coloration and no visual defects.

This demonstrates that a vertical high intensity mixer is an effectivemachine to modify a filler with a functional particle.

Example 12 Modification of ATH with Carbon Black Using an EIRICH Mixer

An EIRICH mixer (RV02E) equipped with a star-type rotor was charged with52.7 kg of ATH (Alcan WH-311) and 1.3 kg of Arosperse F-138 carbon black(Evonik). The mixer was run with an agitator tip speed of 30 m/s and apan rotation speed of 37 rpm. A sample of the mixture was taken after 5minutes. The sample was a fine free-flowing uniformly dark powder.

The sample was subjected to particle size analysis using the sametechnique as described in Example 10. The PSD is depicted in FIG. 17.The curve is relatively narrow and unimodal indicating that a singleparticulate material was generated through modification of the filler(ATH) with a functional particle (carbon black).

The sample was used to cast an experimental Test Plaque (Test Plaque12-A). The same formulation, casting procedure, and plaque finishingprocedure described in Example 10 were used. The Test Plaque was of highquality, exhibiting uniform coloration and no visual defects.

This demonstrates that an EIRCH-type mixer is an effective machine tomodify a filler with a functional particle.

Example 13 Modification of ATH with Carbon Black, Iron Oxide Red, andIron Oxide Yellow Simultaneously Via Shaking and Formation of a FilledAcrylic Composite Using the Modified Filler

A one-gallon paint can was charged with 1,758.42 g ATH (Alcan WH-311)and 9.54 g Arosperse F138 carbon black (Evonik), 16.02 g iron oxide red(Rockwood, Kroma Red, R03097) and 16.02 g iron oxide yellow (Rockwood,Ultra Yellow, YL01888D). The vessel was sealed and then shaken on a RedDevil single-arm paint shaker for 60 minutes. The sample was a finefree-flowing uniformly dark brown powder. Analysis by SEM revealed thepresence of a multitude of particles on the surface of the ATH (see FIG.1A (unmodified ATH) versus FIG. 18 (ATH modified with carbon black, ironoxide red, and iron oxide yellow)).

An experimental Test Plaque (Test Plaque 13-A) was prepared from aliquid prepolymer mixture consisting of 83.4 g methyl methacrylate(MMA), 264.00 g of a 24 wt. % acrylic polymer solution (polymethylmethacrylate of molecular weight approximately 30 kg/mol dissolved inMMA), 4.26 g trimethylolpropane trimethacrylate, 7.10 gtert-butylperoxymaleic acid (PMA-25, Arkema), 0.68 g of Zelec PHunsaturated phosphoric acid ester (Stepan Co.) and 1.50 g AOT-S(Cytec)which were blended at room temperature. While stirring at 300 rpm withan air-driven pitch blade turbine, 635.0 g of the modified ATH describedabove was added over one minute. Mixing was continued for two additionalminutes. The mixture was then transferred to an enclosed vessel wheredissolved gases were removed in vacuo (24 inHg) over a period of twominutes while stirring at 1,000 rpm. While still under vacuum, 2.98 g ofa calcium hydroxide suspension (45 wt. % in solvent) was added viasyringe through a rubber septum. This was immediately followed byaddition of 1.11 g ethylene glycol dimercaptoacetate (GDMA). Aftermixing for 30 seconds, the vacuum was released and the mixture waspoured into a film-lined casting cavity which was pre-heated to 35° C.Film was placed on the backside of the casting, and an insulated coverwas placed on top. The mixture cured within 15 minutes. After allowingthe resultant plaque to cool to room temperature, it was rough-finishedin a drum sander and then sanded with progressively finer grit sandpaper ending with 500-grit to create Test Plaque 13-A, a filledpolymeric material pigmented with dry-blended filler. The Test Plaquewas of high quality, exhibiting uniform coloration and no visualdefects.

This demonstrates that a filler can be modified with multiple functionalparticles in one step using the processes described herein.

Example 14 Modification of ATH with an Azo/Strontium Salt Pigment ViaShaking and Formation of a Filled Acrylic Composite Using the ModifiedFiller

A one-gallon paint can was charged with 1,746.00 g ATH (Alcan WH-311)and 54.00 g Graphtol Fire Red 3RLP (Clariant). The vessel was sealed andthen shaken on a Red Devil single-arm paint shaker for 60 minutes. Thesample was a fine free-flowing uniformly bright red/orange powder.Analysis by SEM revealed the presence of small pigment particles on thesurface of the ATH (see FIG. 1A (unmodified ATH) versus FIG. 19 (ATHmodified with Graphtol Fire Red)).

The sample was used to cast an experimental Test Plaque (Test Plaque14-A). The same formulation, casting procedure, and plaque finishingprocedure as described in Example 13 were used, except for asubstitution with the modified ATH prepared in this example. The TestPlaque was of high quality, exhibiting uniform coloration and no visualdefects.

This demonstrates that a filler can be modified with a pigment describedas a metal salt of an azo compound, using the processes describedherein.

Example 15 Modification of ATH with Titanium Dioxide Via Shaking andFormation of a Filled Acrylic Composite Using the Modified Filler

A one-gallon paint can was charged with 1,746.00 g ATH (Alcan WH-311)and 54.00 g Titanium Dioxide (TiPure R960, DuPont). The vessel wassealed and then shaken on a Red Devil single-arm paint shaker for 60minutes. The sample was a fine free-flowing uniformly white powder.Analysis by SEM revealed the presence of small titanium dioxideparticles on the surface of the ATH (see FIG. 1A (unmodified ATH) versusFIG. 20 (ATH modified with titanium dioxide)).

The sample was used to cast an experimental Test Plaque (Test Plaque15-A). The same formulation, casting procedure, and plaque finishingprocedure as described in Example 13 were used, except for asubstitution with the modified ATH prepared in this example. The TestPlaque was of high quality, exhibiting uniform coloration and no visualdefects.

This demonstrates that a filler can be modified with titanium dioxideusing the processes described herein.

Example 16 Modification of ATH with Fumed Silica (0.2-0.3 Micron) ViaShaking and Formation of a Filled Acrylic Composite Using the ModifiedFiller

A one-gallon paint can was charged with 1,757.5 g ATH (Alcan WH-311) and42.5 g fumed silica, (0.2-0.3 microns, Aldrich). The vessel was sealedand then shaken on a Red Devil single-arm paint shaker for 60 minutes.The sample was a fine free-flowing uniformly white powder. Analysis bySEM revealed the presence of small silica particles on the surface ofthe ATH (see FIG. 1A (unmodified ATH) versus FIG. 21 (ATH modified with0.2-0.3 micron fumed silica)).

The sample was used to cast an experimental Test Plaque (Test Plaque16-A). The same formulation, casting procedure, and plaque finishingprocedure as described in Example 13 were used, except for asubstitution with the modified ATH prepared in this example. The TestPlaque was of high quality, exhibiting uniform coloration and no visualdefects.

This demonstrates that a filler can be modified with an amorphous silicaparticle compound using the processes described herein.

Example 17 Modification of ATH with Fumed Silica (0.007 Micron) ViaShaking and Formation of a Filled Acrylic Composite Using the ModifiedFiller

The procedures for filler modification and formation of a filled acryliccomposite described in Example 16 were repeated exactly, except fumedsilica of particle size 0.007 microns (Aldrich) was used as thefunctional particle. Analysis by SEM again revealed the presence ofsmall silica particles on the surface of the ATH (see FIG. 1A(unmodified ATH) versus FIG. 22 (ATH modified with 0.007 micron fumedsilica)).

Example 18 Modification of ATH with Talc Via Shaking and Formation of aFilled Acrylic Composite Using the Modified Filler

A one-gallon paint can was charged with 1,757.5 g ATH (Alcan WH-311) and42.5 g talc, (D₅₀=10 microns measured by light scattering, ReactAmineTechnology). The vessel was sealed and then shaken on a Red Devilsingle-arm paint shaker for 60 minutes. The sample was a finefree-flowing uniformly white powder.

The sample was used to cast an experimental Test Plaque (Test Plaque18-A). The same formulation, casting procedure, and plaque finishingprocedure as described in Example 13 were used, except for asubstitution with the modified ATH prepared in this example. The TestPlaque was of high quality, exhibiting uniform coloration and no visualdefects.

This demonstrates that a filler can be modified with functionalplatet-type particles using the processes described herein.

Example 19 Modification of ATH with Tinuvin 328 Via Shaking andFormation of a Filled Acrylic Composite Using the Modified Filler

A one-gallon paint can was charged with 1,757.5 g ATH (Alcan WH-311) and42.5 g Tinuvin 328 (BASF). The vessel was sealed and then shaken on aRed Devil single-arm paint shaker for 60 minutes. The sample was a finefree-flowing uniformly white powder.

The sample was used to cast an experimental Test Plaque (Test Plaque19-A). The same formulation, casting procedure, and plaque finishingprocedure as described in Example 13 were used, except for asubstitution with the ATH prepared in this example. The Test Plaque wasof high quality, exhibiting uniform coloration and no visual defects.

This demonstrates that a filler can be modified with a crystalline smallorganic molecule using the processes described herein.

Example 20 Modification of ATH with FEP Powder Via Shaking and Formationof a Filled Acrylic Composite Using the Modified Filler

A one-gallon paint can was charged with 1,757.5 g ATH (Alcan WH-311) and42.5 g fluorinated ethylene-propylene copolymer powder (FEP, DuPont).The vessel was sealed and then shaken on a Red Devil single-arm paintshaker for 60 minutes. The sample was a fine free-flowing uniformlywhite powder.

The sample was used to cast an experimental Test Plaque (Test Plaque20-A). The same formulation, casting procedure, and plaque finishingprocedure as described in Example 13 were used, except for asubstitution with the modified ATH prepared in this example. The TestPlaque was of high quality, exhibiting uniform coloration and no visualdefects.

This demonstrates that a filler can be modified with semicrystallinepolymeric particles using the processes described herein.

Example 21 Modification of ATH with PFA Powder Via Shaking and Formationof a Filled Acrylic Composite Using the Modified Filler

A one-gallon paint can was charged with 1,757.5 g ATH (Alcan WH-311) and42.5 g perfluoroalkoxy polymer powder (PFA, DuPont). The vessel wassealed and then shaken on a Red Devil single-arm paint shaker for 60minutes. The sample was a fine free-flowing uniformly white powder.

The sample was used to cast an experimental Test Plaque (Test Plaque21-A). The same formulation, casting procedure, and plaque finishingprocedure as described in Example 13 were used, except for asubstitution with the modified ATH prepared in this example. The TestPlaque was of high quality, exhibiting uniform coloration and no visualdefects.

This again demonstrates that a filler can be modified withsemicrystalline polymeric particles using the processes describedherein.

Comparative Example 1

A control sample was prepared for comparative analysis against theexperimental samples prepared for Examples 22 and 23, described below.The control sample is a commercially sold ATH-filled acrylic solidsurface material (Corian®, available from DuPont) composite sheet thatis a highly saturated black color. The material is pigmented with carbonblack at a level of 0.058 wt %. The carbon black was introduced to aliquid prepolymer mixture via a dispersion of general composition knownto those skilled in the art. The control sample was sanded identicallyto the experimental samples, as described below in Example 22. Aftermeasuring the color values of the control sample (Table 7) it was sawninto ten Test Plaques, Comparative Test Plaques 1A, 1B, 1C, 1D, 1E, 1F,1G, 1H, 1I, and 1J. The control sample provides a comparison of filledpolymeric materials that are pigmented by traditional liquid dispersionsagainst filled polymeric materials that are pigmented by dry-blendingthe pigment and filler prior to incorporation into a liquid prepolymermixture, and also to filler that is dyed before incorporation into aliquid prepolymer mixture.

Example 22

Pilot Scale Casting of Filled Acrylic Composition Comprising ATHModified with Carbon Black at 0.094 wt. %

A batch of ATH modified with Arosperse F138 carbon black at a low level(0.094 wt. %) was made by dry-blending via shaking as described inExample 3 to make dry-blended carbon black modified ATH.

A liquid prepolymer mixture consisting of 2.5 kg methyl methacrylate(MMA), 10.1 kg of a 24 wt. % acrylic polymer solution (polymethylmethacrylate of molecular weight approximately 30 kg/mol dissolved inMMA), 152.8 g trimethylolpropane trimethacrylate, 280.2 gtert-butylperoxymaleic acid (PMA-25, Arkema), 23.8 g of Zelec PHunsaturated phosphoric acid ester (Stepan Co.) and 52.5 g AOT-S(Cytec)was blended at room temperature in a lined, 10-gallon steel vessel usinga combination marine prop/pitch blade turbine impeller. While stirringat 300 rpm, 21.7 kg of the dry-blended carbon black modified ATHdescribed above was added over one minute. Blending was continued fortwo additional minutes. The mixture was then transferred to an enclosedvessel where dissolved gases were removed in vacuo (24 inHg) over aperiod of two minutes while stirring at 500 rpm. While still undervacuum, 117.7 g of a calcium hydroxide suspension (45 wt. % in solvent)was added via syringe through a rubber septum. This was immediatelyfollowed by addition of 44.0 g of ethylene glycol dimercaptoacetate(GDMA). After mixing for 30 seconds, the vacuum was released and theliquid prepolymer mixture was poured into a film-lined casting cavity.Film was placed on the backside of the casting, and an insulated coverwas placed on top. The mixture cured within 15 minutes. After allowingthe resultant sheet to cool to room temperature, it was rough-finishedin a drum sander and then sanded with a sequence of progressively finergrit sand paper ending with 240-grit to create a low level dry-blendedexperimental sample. The experimental sample with a low level of pigmentdry-blended onto filler was of high visual quality, exhibiting uniformcolor throughout the specimen, with no blemishes or other defects.

Color measurements were made of the low level experimental sample usinga Hunter Miniscan spectrophotometer (Table 3). The color of the controlsample, which had carbon black introduced via a standard liquiddispersion, and that of the low level experimental sample made usingdry-blended carbon black modified ATH were approximately the same.

TABLE 3 Initial Color Values L a b Control Sample 27.07 −0.53 −2.48 LowLevel Experimental Sample 26.91 −0.61 −2.68

The low level experimental sample was then sawn into three pieces tocreate Test Plaques 22A, 22B, and 22C.

Test Plaque 22A and Comparative Test Plaque 1A were subjected to waterblush testing by immersion in 72° C. water for 16 hours. Colormeasurements were made on each sample before and after the test and ΔEvalues were calculated (Table 4). The data shows that Comparative TestPlaque 1A had significantly more whitening due to water blush than wasobserved for Test Plaque 22A. This demonstrates that dry-blended fillerprovides colored filled polymer materials having improved resistance towhitening due to water blush.

TABLE 4 Calculated Color Change After Water Blush Testing. ΔEComparative Test Plaque lA 5.75 Test Plaque 22A 1.18

Comparative Test Plaque 1B and Test Plaque 22B were subjected to athermobending test. Both samples were heated to 160° C. in a doubleplaten oven. Afterwards, they were placed over a curved form with a 3inch radius. The specimens were allowed to cool completely in a vacuumpress. The color of the center region of each sample was read before andafter the test. The results provided in Table 5 below show asignificantly lower color change for Test Plaque 22B compared toComparative Test Plaque 1B. This demonstrates that dry-blended fillerprovides colored filled polymer materials having improved resistance towhitening due to thermobending.

TABLE 5 Calculated Color Change After Thermobending ΔE Comparative TestPlaque 1B 2.70 Test Plaque 22B 0.64

Example 23 Pilot Scale Casting of Filled Acrylic Composition ComprisingATH Dry-Blended with Carbon Black at 2.36 wt. %

A batch of ATH modified by with Arosperse F138 carbon black at a highlevel (2.36 wt. %) was made by dry-blending via shaking as described inExample 3, to make dry-blended carbon black modified ATH.

A liquid premix consisting of 2.4 kg methyl methacrylate (MMA), 9.7 kgof a 24 wt. % acrylic polymer solution (polymethyl methacrylate ofmolecular weight approximately 30 kg/mol dissolved in MMA), 147.0 gtrimethylolpropane trimethacrylate, 269.5 g tert-butylperoxymaleic acid(PMA-25, Arkema), 23.8 g of Zelec PH unsaturated phosphoric acid ester(Stepan Co.) and 52.5 g AOT-S (Cytec) was blended at room temperature ina lined, 10-gallon steel vessel using a combination marine prop/pitchblade turbine impeller. While stirring at 300 rpm, 22.2 kg of the carbonblack modified ATH described above was added over one minute. Mixing wascontinued for two additional minutes. The mixture was then transferredto an enclosed vessel where dissolved gases were removed in vacuo (24inHg) over a period of two minutes while stirring at 500 rpm. Whilestill under vacuum, 113.2 g of a calcium hydroxide suspension (45 wt. %in solvent) was added via syringe through a rubber septum. This wasimmediately followed by addition of 42.3 g ethylene glycoldimercaptoacetate (GDMA). After mixing for 30 seconds, the vacuum wasreleased and the mixture was poured into a film-lined casting cavity.Film was placed on the backside of the casting, and an insulated coverwas placed on top. The mixture cured within 15 minutes. After allowingthe resultant sheet to cool to room temperature, it was rough-finishedin a drum sander and then sanded with progressively finer grit sandpaper ending with 240-grit to create a high level experimental sample.The experimental sample with a high level of pigment dry-blended ontofiller was of high visually quality, exhibiting uniform color throughoutthe specimen, with no blemishes or other defects.

Color measurements were made using a Hunter Miniscan spectrophotometer(Table 6). The color of the high level experimental sample wassignificantly darker than that of the control sample that was made inComparative Example 1.

TABLE 6 Initial Color Values L a b Control Sample 27.07 −0.53 −2.48 HighLevel Experimental Sample 23.81 −0.39 −1.45

After measuring the color values of the high level experimental sampleit was sawn into five pieces to create Test Plaques 23A, 23B, 23C, 23Dand 23E.

Test Plaque 23A and Comparative Test Plaque 1C were subjected to a waterblush test by immersion in 72° C. water for 16 hours. Color measurementswere made after the test and ΔE values were calculated compared to theinitial values (Table 7). A significant decrease in whitening due towater blush was observed for Test Plaque 23A as compared to the controlof Comparative Test Plaque 1C. This demonstrates an improvement in waterblush whitening for dry-blended pigment modified filler than forpigments incorporated by traditional liquid dispersions.

TABLE 7 Calculated Color Change After Water Blush Testing. ΔEComparative Test Plaque 1C 5.75 Test Plaque 23A 0.52

Test Plaque 23B and Comparative Test Plaque 1D were subjected to athermobending test. Both Test Plaques were heated to 160° C. in a doubleplaten oven. Afterwards, the Test Plaques were placed over a curved formwith a 3 inch radius. The specimens were allowed to cool completely in avacuum press. The color of the center region of each Test Plaque wasread after the test and compared to the initial value as shown in Table6. The results provided in Table 8 below show a significantly lowercolor change for the Test Plaque 23B as compared to the control sampleof Comparative Test Plaque 1D.

TABLE 8 Calculated Color Change After Thermobending ΔE Comparative TestPlaque 1D 2.70 Test Plaque 23B 0.20

A control sample (Comparative Test Plaque 1E), a low level experimentalsample (Test Plaque 22C), and a high level experimental sample (TestPlaque 23C) were subjected to constant force scratch testing. AMicro-Scratch Tester (CSM Instruments) equipped with a 1 mm steel ballwas used to scratch each specimen using a constant force of 15 N over apath length of 20 mm. FIG. 23 shows the resulting scratch on each TestPlaque. The control sample scratch whitens considerably. While the lowlevel experimental sample scratch whitens in a similar manner to thecontrol, scratch whitening is dramatically reduced for the high levelexperimental sample. Images of the scratched specimens were analyzedusing the ImageJ software (version 1.45 s) (an image processing programavailable from the National Institutes of Health). Histograms of thegrey values found within an area inscribed about each scratch weregenerated (FIG. 23). Consistent with the appearance of the scratches,the control sample and the low level experimental sample exhibit apopulation of lighter values while the high level experimental sampledoes not. The histogram data are summarized in Table 9 below. Relativeto the control and the low level experimental sample, the high levelexperimental sample exhibits a lower mean grey value, a lower minimumand maximum grey value, and a lower mode of grey values. Further, aprofile plot of the three samples is given in FIG. 24. This plot showsthe grey value along the scratch from left to right as depicted in FIG.24. The profile curve for the high level experimental sample issignificantly lower than that of the control or low level sample.

TABLE 9 Parameters from Grey Value Histogram (FIG. 24) Low High ControlLevel Level Count 1788 1800 1812 Mean 56.99 60.43 29.51 Std Dev 34.0433.22 8.76 Min 30 33 16 Max 170 164 70 Mode 39(225) 42(241) 25(179)

Control sample Comparative Test Plaque 1E, and experimental samples TestPlaque 22D and Test Plaque 23D were subjected to an impact whiteningtest. A Gardner impact tester fitted with a 2-lb tip was used to strikeeach sample successively along its length with increasing force. Avisual determination was made as to the minimum force required to causea whitening defect. While the force required to impart a whiteningdefect in the control sample was in the 2-4 in-lb range, the forcerequired to impart a whitening defect in the experimental sample was inthe 6-8 in-lb range indicating a resistance to whitening due to impact.This demonstrates an improvement in impact whitening for dry-blendedpigment modified filler compared to pigments incorporated by traditionalliquid dispersions.

Control sample Comparative Test Plaque 1F and the experimental sampleTest Plaque 23E were subjected to a temperature resistance test. Aheated block, thermostatically controlled to 250° C., was placed on thesurface of each sample for 5 minutes. The color of the sample where thetest was conducted was read before and after. Table 10 below shows asignificant difference in whitening due to incidence with hightemperature for the experimental sample versus the control (3.98 versus13.02 ΔE units). FIG. 25 depicts the appearance of each sample beforeand after the test. The results provided in Table 10 below show asignificantly lower color change for the Test Plaque 23E as compared tothe control sample of Comparative Test Plaque 1F. This demonstrates animprovement in high temperature whitening for dry-blended pigmentmodified filler compared to pigments incorporated by traditional liquiddispersions.

TABLE 10 Calculated Color Change After Hot Block Testing ΔE ComparativeTest Plaque 1F 13.02 Test Plaque 23E 3.98

Comparative Example 2

A dyed aluminum trihydrate filler was synthesized as described inExample 2 of U.S. Pat. No. 7,863,369. A four liter reaction kettle wascharged with an aqueous suspension of Alumina Trihydrate (ATH,Rio-Tinto-Alcan, WH311—540 g) in de-ionized water (3,377 g). The pH ofthe aqueous suspension was adjusted to ˜3.5 using a dilute solution ofnitric acid in water (˜1 mL of a 14% solution). Reactive Red 198 powder(4.22 g, Reactive Red 198 is a triazine dye having a sulfatoethylsulfonefunctional group, and was obtained from Organic Dyestuffs Corp, 1015Highway 29 N, Concord, N.C. 28025, Product No. 16198OR12) was added tothe reaction kettle. The resulting ATH-dye suspension was warmed to 65°C. for a one hour interval with constant stirring. The aqueoussuspension was maintained at a temperature of between 60° C. and 70° C.for two hours with constant stirring. After the two hour heatinginterval was complete, the suspension was allowed to cool and settleovernight without stirring. Excess liquid was decanted from the settledATH, and the moist solid obtained was dried at 60° C. to 70° C. first ina hot air oven and then under vacuum (>740 mm Hg). Any agglomerateswhich formed during the drying steps were broken up by ball milling withceramic media.

A dyed-filler control sample of filled polymeric material comprised ofan acrylic matrix and dyed aluminum trihydrate filler was synthesized ina 1500 mL resin kettle (10.5×23 cm) fitted with kettle top having portsfor a temperature probe, air-driven stirrer, rubber septum and anAllihn™ type reflux condenser. The following ingredients weresequentially weighed into the kettle:

PMA-25 (t-Butyl Peroxymaleic Acid Paste, Arkema) 17.16 g

Aerosol-OT Surfactant (Cytec Industries) 2.74 g

TRIM (Trimethylolpropane Trimethacrylate, Sartomer) 7.46 g

MMA (Methyl Methacrylate, Lucite® International 56.07 g

Zelec® PH (unsaturated phosphoric acid ester, Stepan Co) 1.23 g

Polymer Syrup (24% PMMA-30,000 Daltons dissolved in MMA) 587.35 g

Quinacridone Red Pigment Paste (Penn Color, PC9S172) 6.84 g

After mixing these ingredients using a High Speed Disperser (HSD) Blade(60 mm Diameter—INDCO Cowles Type) at 500 rpm for one minute at roomtemperature, 1116.0 g of dyed ATH (prepared as described above) wasadded portion wise over a two minute interval. During the portion wiseaddition of the dyed ATH, the rpm of the HSD was incrementally increasedto about 1,500 rpm. After the dyed ATH addition was complete, the HSDspeed was increased to 2,000 rpm and maintained for 10 minutes. Theresulting mixture was then evacuated (Reflux condenser cooled to −10°C.) at 75 Torr (about 27 inches of Hg) for two minutes with 1,000 rpmstirring (3′-four blade prop). The mixture was warmed to 45° C. using awaterbath. The mixing rpm was increased to 1,500 rpm and the followingingredients were sequentially injected via syringe in rapid succession:De-mineralized water 0.25 gCalcium Hydroxide (45% Suspension, DuPont) 7.21 gThiocure® GDMA (Glycol Dimercaptoacetate, Evans) 2.69 g

The resulting slurry was allowed to mixture (1,500 rpm) at 45° C. forabout 10 sec. Stirring was discontinued and the vacuum was released withair. The initiated mixture was poured into a 15 mm thick sheet castingmold within a one minute interval. The time required to achieve a peaktemperature of 138° C. was approximately 6 minutes. The addition of theGDMA was considered “Time Zero”. Upon cooling, the hardened, polymerizedcomposite plaque was removed from the mold after about one hour andrough-finished on a drum sander and then sanded with progressively finergrit sand paper ending with 240-grit to create a dyed-filler controlsample. After measuring the color values of the dyed-filler controlsample it was sawn into four Test Plaques, Comparative Test Plaques 2A,2B, 2C, and 2D.

Color Change Due to Hot Water Immersion (Water Blush Testing)

Comparative Test Plaque 1G as a control sample, and Comparative TestPlaque 2A as the experimental sample were subjected to a water blushtest by immersion in 72° C. water for 16 hours. Color measurements weremade on each sample after the immersion and ΔE values were calculated(Table 11). Comparative Test Plaque 2A (dyed ATH) exhibits asignificantly larger color change after hot water immersion, compared tothe control (Comparative Test Plaque 1G—liquid dispersion).

TABLE 11 Calculated Color Change after Hot Water Immersion ΔEComparative Test Plaque 1G 1.99 Comparative Test Plaque 2A 9.56Degree of Whitening Due to Thermobending

Comparative Test Plaque 1H as a control sample, and Comparative TestPlaque 2B as the experimental sample were subjected to a thermobendingtest. Each piece was heated to 160° C. in a double platen oven.Afterwards, the specimens were placed over a curved form with a 3 inchradius. The Test Plaques were allowed to cool completely in a vacuumpress. The color of the center region of each Test Plaque was readbefore and after the test. The results provided in Table 12 belowindicate that there is no significant difference in the color change dueto thermobending between each sample.

TABLE 12 Calculated Color Change After Thermobending ΔE Comparative TestPlaque 1H 2.56 Comparative Test Plaque 2B 3.10Degree of Scratch Whitening

Comparative Test Plaque 1I and Comparative Test Plaque 2B were subjectedto constant force scratch testing. A Micro-Scratch Tester (CSMInstruments) equipped with a 1 mm steel ball was used to scratch eachspecimen using a constant force of 15 N over a path length of 20 mm.FIG. 26 shows the resulting scratch on each specimen. Both the liquiddispersion sample (Comparative Example 1I) and the sample made using thedyed filler (Comparative Example 2B) scratch-whiten considerably. Imagesof the scratched Test Plaques were analyzed using the ImageJ software(version 1.45 s). Histograms of the grey values found within an areainscribed about each scratch were generated (FIG. 26). Consistent withthe appearance of the scratches, both Test Plaques exhibit a significantpopulation of lighter values. The histogram data are summarized in Table13 below. While the mean grey value of the liquid dispersion sample issomewhat higher than the dyed ATH sample, the latter has a highermaximum grey value. A profile plot of both samples is given in FIG. 27.This plot shows the grey value along the scratch from left to right asdepicted in FIG. 26. The profile curves of the scratches of the twosamples are quite similar. When all of the visual data is takentogether, it can be concluded that no appreciable difference in theintensity of scratch whitening exists.

TABLE 13 Parameters from Grey Value Histogram (FIG. 26) Liquid DyedDispersion ATH Count 1800 1800 Mean 122.167 104.873 Std Dev 32.35342.232 Min 93 65 Max 232 242 Mode 106(127) 80(128)Degree of Whitening Due to High Temperature

Comparative Test Plaque 1J and Comparative Test Plaque 2C were subjectedto a temperature resistance test. A heated block, thermostaticallycontrolled to 250° C., was placed on the surface of each sample for 5minutes. The color of the Test Plaques were measured after the hot blockwas removed. The results provided in Table 14 below indicate that thereis no significant difference in the color change due to incidence withhigh temperature between each sample.

TABLE 14 Calculated Color Change after Hot Block Test ΔE ComparativeTest Plaque 1J 1.99 Comparative Test Plaque 2C 9.56

What is claimed is:
 1. A process comprising the steps of: (i)manufacturing modified filler particles comprising a filler particlemodified with discrete functional particles, the process comprisingdry-blending filler particles with discrete functional particles in amixer until said discrete functional particles are bound, adhered, orassociated to the filler, (ii) incorporating the modified fillerparticles of step (i) into a liquid prepolymer mix, wherein the fillerparticles and the discrete functional particles remain associated witheach other.
 2. The process of incorporating the modified fillerparticles of claim 1 into the liquid prepolymer of claim 1 wherein theprocess is selected from melt processing, powder coating, solutionprocessing, slip casting, tape casting, vibrocompaction, compressionmolding, sintering, extrusion, injection molding, or any combinationthereof.
 3. The process of claim 1 wherein the discrete functionalparticles are pigment particles.